Objective To determine whether, and to what extent, physical activity interventions affect the overall activity levels of children.Design Systematic review and meta-analysis.Data sources Electronic ...databases (Embase, Medline, PsycINFO, SPORTDiscus) and reference lists of included studies and of relevant review articles.Study selection Design: randomised controlled trials or controlled clinical trials (cluster and individual) published in peer reviewed journals. Intervention: incorporated a component designed to increase the physical activity of children/adolescents and was at least four weeks in duration. Outcomes: measured whole day physical activity objectively with accelerometers either before or immediately after the end of the intervention period.Data analysis Intervention effects (standardised mean differences) were calculated for total physical activity, time spent in moderate or vigorous physical activity, or both for each study and pooled using a weighted random effects model. Meta-regression explored the heterogeneity of intervention effects in relation to study participants, design, intervention type, and methodological quality.Results Thirty studies (involving 14 326 participants; 6153 with accelerometer measured physical activity) met the inclusion criteria and all were eligible for meta-analysis/meta-regression. The pooled intervention effect across all studies was small to negligible for total physical activity (standardised mean difference 0.12, 95% confidence interval 0.04 to 0.20; P<0.01) and small for moderate or vigorous activity (0.16, 0.08 to 0.24; P<0.001). Meta-regression indicated that the pooled intervention effect did not differ significantly between any of the subgroups (for example, for total physical activity, standardised mean differences were 0.07 for age <10 years and 0.16 for ≥10 years, P=0.19; 0.07 for body mass index across the entire range and 0.22 for exclusively overweight/obese children, P=0.07; 0.12 for study duration ≤6 months and 0.09 for >6 months, P=0.71; 0.15 for home/family based intervention and 0.10 for school based intervention, P=0.53; and 0.09 for higher quality studies and 0.14 for lower quality studies, P=0.52).Conclusions This review provides strong evidence that physical activity interventions have had only a small effect (approximately 4 minutes more walking or running per day) on children’s overall activity levels. This finding may explain, in part, why such interventions have had limited success in reducing the body mass index or body fat of children.
Background
Mothers often do not realize when their child is overweight. We aimed to compare mothers' perceptions of children's weight before and during puberty, and to explore factors at 7 years ...predicting recognition of overweight at 16 years.
Methods
Mothers of 237 children (136 boys) from the EarlyBird study estimated their own weight category and that of their child aged 7 years and 16 years. The children estimated their own weight category at 16 years. Annual measures: body mass index standard deviation score (BMIsds), per cent fat, physical activity. Pubertal development assessed by age at peak height velocity (APHV). Maternal measures: BMI, education, socio‐economic status.
Results
At 7 years 21% of girls and 16% of boys were overweight or obese, rising to 27% and 22% respectively at 16 years. The accuracy of the mother's perception of her child's weight category improved from 44% at 7 years to 74% at 16 years, but they were less able to judge overweight in sons than daughters. The mothers' level of concern about overweight was greater for girls than boys, and increased for girls (52% mothers of overweight/obese girls were worried at 7 years, 62% at 16 years), but remained static in the boys (42% vs. 39%). Over 80% of the youngsters realized when they were overweight, but 25% normal‐weight girls also classed themselves as overweight. Only BMI predicted a mother's ability to correctly perceive her child's weight. Neither her awareness, nor concern, about the child's weight at 7 years had any impact on the trajectory of the child's BMI from 7 years to 16 years.
Conclusions
Parents are central to any successful weight reduction programme in their children, but will not engage while they remain ignorant of the problem. Crucially, any concern mothers may have about their child's excess weight at 7 years appears to have no impact on subsequent weight change.
Steroid receptor RNA activator (SRA), the only known RNA coactivator, augments transactivation by nuclear receptors (NRs). We identified SLIRP (
SRA stem-
loop
interacting
RNA binding
protein) ...binding to a functional substructure of SRA, STR7. SLIRP is expressed in normal and tumor tissues, contains an RNA recognition motif (RRM), represses NR transactivation in a SRA- and RRM-dependent manner, augments the effect of Tamoxifen, and modulates association of SRC-1 with SRA. SHARP, a RRM-containing corepressor, also binds STR7, augmenting repression with SLIRP. SLIRP colocalizes with SKIP (Chr14q24.3), another NR coregulator, and reduces SKIP-potentiated NR signaling. SLIRP is recruited to endogenous promoters (pS2 and metallothionein), the latter in a SRA-dependent manner, while NCoR promoter recruitment is dependent on SLIRP. The majority of the endogenous SLIRP resides in the mitochondria. Our data demonstrate that SLIRP modulates NR transactivation, suggest it may regulate mitochondrial function, and provide mechanistic insight into interactions between SRA, SLIRP, SRC-1, and NCoR.
Summary
What is already known about this subject
South Asian children at birth are thinner, but more adipose and more resistant to insulin than White Caucasian children.
South Asian adults are more ...adipose and more insulin resistant, but their greater adiposity does not fully explain the difference in insulin resistance.
South Asian children at 8 y are more insulin resistant than White Caucasian children.
What this study adds
The BMI of South Asian children at 6 y is distributed normally, while that of White Caucasian children is heavily skewed.
South Asian children at 6 y are slimmer, and the boys, but not the girls, are more adipose.
South Asian boys, but not girls are more insulin resistant. Both genders metabolically less healthy, but their adiposity explains only part of the difference.
Background/Aims
The concept of the ‘thin–fat’ Indian baby is well established, but there is little comparative data in older children, and none that examines the metabolic correlates. Accordingly, we investigated the impact of body composition on the metabolic profiles of Asian Indian and white UK children.
Methods
Body mass index (BMI), waist circumference, sum of four skin‐folds, % body fat (by dual‐energy X‐ray absorptiometry), glucose, insulin, insulin resistance (Homeostasis Model Assessment), trigylcerides, cholesterol total, low‐density lipoprotein, high‐density lipoprotein {HDL}, total/HDL ratio and blood pressure (systolic, diastolic and mean arterial) were measured in 262 white Caucasian children from Plymouth, UK (aged 6.9 ± 0.2 years, 57% male), and 626 Indian children from rural villages around Pune, India (aged 6.2 ± 0.1 years, 53% male).
Results
Indian children had a significantly lower BMI (boys: −2.1 kg m−2, girls: −3.2 kg m−2, both P < 0.001), waist circumference (P < 0.001) and skin‐fold thickness (P < 0.001) than white UK children, yet their % body fat was higher (boys +4.5%, P < 0.001, girls: +0.5%, P = 0.61). Independently of the differences in age and % body fat, the Indian children had higher fasting glucose (boys +0.52 mmol L−1, girls +0.39 mmol L−1, both P < 0.001), higher insulin (boys +1.69, girls +1.87 mU L−1, both P < 0.01) and were more insulin resistant (boys +0.25, girls +0.28 HOMA‐IR units, both P < 0.001).
Conclusions
The ‘thin–fat’ phenotype observed in Indian babies is also apparent in pre‐pubertal Indian children who have greater adiposity than white UK children despite significantly lower BMIs. Indian children are more insulin resistant than white UK children, even after adjustment for adiposity.
A two-step approach is proposed to predict the modulus of asphalt concrete from existing micromechanical models. The asphalt concrete microstructure is represented by a two-phase model, which ...consists of a large spherical aggregate particle surrounded by a spherical shell of fine aggregate-filler-binder mixture as the matrix. The fine aggregate-filler-binder mixture is further represented by a two-phase model, which treats fine aggregate as a spherical inclusion and the mixture of filler and binder as the matrix. The modulus of asphalt concrete is predicted from the volumetric fractions, Poisson’s ratios, and moduli of the aggregate and filler-binder mixture by applying the appropriate two-phase models in two steps. An asphalt concrete and two mixtures that replicate the fine aggregate-filler-binder submixture and the filler-binder submixture in the asphalt concrete have been tested for modulus. The tests results show that the predicted results from the appropriate models reasonably approximate the measured results.
High-throughput gene sequencing has revolutionized the process used to identify novel molecular targets for drug discovery. Thousands of new gene sequences have been generated but only a limited ...number of these can be converted into validated targets likely to be involved in disease. We describe here some of the approaches used at SmithKline Beecham to select and validate novel targets. These include the identification of selective tissue gene product expression, such as for cathepsin K, a novel osteoclast-specific cysteine protease. We also describe the discovery and functional characterization of novel members of the G-protein coupled receptor superfamily and their pairing with natural ligands. Lastly, we discuss the promises of gene microarrays and proteomics, developing technologies that allow the parallel analyses of tissue expression patterns of thousands of genes or proteins, respectively.
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